A comparative study of hydrothermal aging effect on cerium and lanthanum doped Cu/SSZ-13 catalysts for NH3-SCR

• 作者: Di Deng Shujun Deng Dandan He Zhiheng Wang Zhipeng Chen Yi Ji Guoping Yan Guangjin Hou Licheng Liu Hong He
• 来源期刊: 稀土学报（英文版）
• 年，卷（期）: 2021,（8）
• 所属期刊栏目: RARE EARTH CATALYSIS
• 页码范围: 969-978
• 页数: 10页
• 语种: 英文

摘要

Ce-or La-doped Cu/SSZ-13 catalysts were prepared by a hydrothermal method and Cu,Ce or La ions were incorporated through stepwise ion exchange.The catalyst activity was measured for the ammonia se-lective catalytic reduction reaction.The structure and composition of catalyst were characterized by using X-ray diffraction,scanning electron microscopy,inductively coupled plasma mass spectrometry solid-state NMR,NH3-TPD techniques,and the active components were examined by XPS and XANES.The results indicate that the Ce and La doping can both completely preserve the SCR activity of Cu/SSZ-13 above 300 ℃,but there is also a decrease of activity below 200 ℃.On the other hand,Ce doping is beneficial to the formation of framework aluminum,stabilizes molecular sieve framework and Cu active sites of Cu/SSZ-13,thereby improves the catalyst hydrothermal stability.But La doping will decrease the amount of framework aluminum and Cu active sites of Cu/SSZ-13 after hydrothermally aging,even destroy zeolite CHA structure.This is quite harmful to the catalyst hydrothermal stability.